Key Points
- Scientists have created a new liquid that can switch between a free-flowing fluid and a thick, nearly solid state.
- The change is controlled by temperature, which alters the shape and stiffness of tiny particles in the liquid.
- At low temperatures, the particles are stiff and irregular; however, at higher temperatures, they become soft and round, allowing the liquid to flow easily.
- The material can also “reset” itself from a clumpy state to a fluid one with a simple heating and cooling cycle.
Imagine a liquid that can flow like water one moment and then instantly stiffen into a thick, almost solid state. Now, imagine you could control this change just by adjusting the temperature. Researchers from the University of Chicago and NYU have done just that, creating a new “smart liquid” using tiny, shape-shifting particles. The research was published in Proceedings of the National Academy of Sciences.
This new material is a dense mixture of special rubbery particles in a fluid. The key is that these particles change their shape and stiffness in response to changes in temperature. At low temperatures, the particles are stiff and have irregular, jagged shapes. This causes them to lock together under pressure, resulting in the liquid thickening dramatically, similar to the unusual behavior observed when mixing cornstarch and water.
But when the liquid is heated to around 45-50°C (about 113-122°F), the particles become soft and round. In this state, they slide past each other easily, and the liquid flows freely again. The researchers demonstrated that they could repeatedly flip this switch back and forth.
This technology could solve major problems in industries that use thick mixtures, such as paints, cement, or even 3D printing materials. Often, these materials can jam up machinery. With this new liquid, a manufacturer could simply heat the mixture slightly to restore its smooth flow.
The material also has a built-in “reset button.” After sitting for a while, these types of liquids can become clumpy and difficult to work with. But by briefly heating and cooling this new mixture, the particles reset themselves, and the liquid becomes fluid again without any stirring. This provides engineers with a powerful new way to control the behavior of materials on demand.
